Investigation of the hormonal regulation of mating behavior in the cricket Teleogryllus commodus, in particular the role of the Corpora allata and the Pars intercerebralis. Mating-tests between operated and normal crickets will be conducted, biological determination of hormonal titers will be made, and replacement therapy will be performed. Study of circadian locomotor rhythms of early larval instars in the cricket Teleogryllus commodus, to establish at what larval stage circadian control becomes evident.